Zanubrutinib and Eltrombopag as Second-line Treatment in Adults With Primary Immune Thrombocytopenia

Inclusion Criteria: 1. Primary immune thrombocytopenia (ITP) confirmed by excluding other supervened causes of thrombocytopenia; 2. Patients with chronic low platelet count (less than 30,000/µL) for 6 months who have failed at least one treatment for chronic low platelet count 2\. Patients who did not achieve a sustained response to treatment with full-dose corticosteroids for a minimum duration of 4 weeks or who relapsed during steroid-tapering or after its discontinuation 3. Willing and able to sign written informed consent Exclusion Criteria: 1. Secondary immune thrombocytopenia (e.g., patients with HIV, HCV, Helicobacter pylori infection or patients with systemic lupus erythematosus) 2. congestive heart failure 3. severe arrhythmia 4. nursing or pregnant women 5. aspartate aminotransferase and alanine transaminase levels ≥ 3× the upper limit of the normal threshold criteria 6. creatinine or serum bilirubin levels each 1•5 times or more than the normal range 7. active or previous malignancy 8. Unable to do blood routine test for the sake of time, distance, economic issues or other reasons 9. History of clotting disorder